Electrical connector with slotted beam contact

Abstract: An electrical connector, or wire connecting block, is of the type for electrically interconnecting a set of first conductors to an associated set of second conductors. The connector comprises a dielectric housing (12) defined by a pair of side walls (14) and containing a plurality of through cavities (22) therebetween. The cavities (22) being for slidably receiving a like plurality of slotted beam contacts (24) and each having a first uniform width over a portion of its length, a second portion having a uniform width greater than the first uniform width, and an angled wall transition portion (28) between the uniform portions. Externally, the housing is provided with a like plurality of thin walled sections (32) along one of the side walls (14), where each said thin walled section (32) is aligned with a corresponding angled wall transition portion (28) within a given cavity. Into the cavity (22) a slotted beam planar contact (24) is received, where the contact comprises a mid body portion (40) and a pair of opposing end portions (46,48) each containing an insulation displacing slot (54,56) for receiving a conductor. The mid body portion (40) includes a lance (70) struck therefrom and angled to abut the angled wall transition portion (28) whereby to secure the contact against movement in a first direction. Finally, after loading the contact into the cavity, the thin walled section (32) is partially severed, such as by a sharp tool to allow hinging movement of the section (32) into its respective cavity adjacent said lances, whereby to secure the contact against movement in a second direction.

Description: This invention relates to an electrical connector of the type known as a wire connecting block, where such connecting block typically includes a plurality cf parallelly arranged slotted beam contacts. A wire connecting block is a commercial product used in the telephone industry to electrically interconnect a set of first conductors to an associated set of second conductors. An early example of a wire connecting block is taught in US-A-3,611,264. The connector thereof includes an indexing strip and a connecting block the latter of which carries a plurality cf slotted beam contacts. The indexing strip has a plurality of uniform height, spaced-apart teeth along its length. These teeth aid in indexing a first set of conductors. A corresponding plurality of uniform height, spaced-apart teeth carried by the connecting block serve to index a second set of conductors to be cross-connected through the slotted beam contacts to the first set of conductors. There have been various improvements thereto over the years, such as those proposed by US-A-3,798,587 and 4,118,095. However, none of the documents cited hereinabove appears to be directed to the stability of the connector, particularly in fixedly securing the slotted beam contacts therein. It will be appreciated that a considerable normal force must be applied to the contact to effect termination thereto by the displacing of the conductor insulation and pushing such conductor into the slot between the contact arms. In the wire connecting blocks sold commercially, most experience considerable "play" in the seated contacts. Attempts have been made to reduce this "play" by the provision of an insert projecting through the wall of the connector housing and through the cavity. However, even with this approach, some "play" remains. The present invention, by a unique cooperation between the housing and the contained contacts, substantially eliminates the "play" and provides improved stability of the connector during termination thereof. According to the invention there is provided an electrical connector of the type for electrically interconnecting a set of first conductors to an associated set of second conductors, the connector comprising a dielectric housing defined by a pair of side walls and containing a plurality of through cavities therebetween, where each said cavity is adapted to receive a slotted beam planar contact, characterised in that the length of said cavities are provided with a first uniform width over a portion of its length, a second portion having a uniform width greater than said first uniform width, and an angled wall transition portion between said uniform portions; and, a like plurality of thin walled sections along one of said side walls, where each said thin walled section is aligned with a corresponding angled wall transition portion within a given cavity each said slotted beam planar contact comprising a mid portion and a pair of opposing end portions, each containing an insulation displacing slot for receiving a conductor, said mid portion having a lance struck therefrom and angled to abut said angled wall transition portion, whereby to secure said contact against movement in a first direction, and said thin walled sections being partially severable to allow hinging movement thereof into the respective cavities adjacent said lances, whereby to secure said contact against movement in a second direction, i.e. in the opposite direction during termination of the other set of conductors. A method of securing an electrical contact in the cavity of an insulating housing by severing a thinned wall portion of the cavity and hingedly moving the severed portion into the contact receiving cavity is described in US-A-3 993 396. An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings in which: FIGURE is an exploded perspective view of the type of an electrical connector suitable for electrically Interconnecting a first set of conductors to an associated second set of conductors by the practice of this invention; FIGURES 2 to 4 are a sequence of sectional views illustrating the loading of a contact into a dielectric housing, followed by views cf the system for fixedly securing the contact within the housing; FIGURE 5 is an enlarged sectional view, similar to Figure 4, illustrating the manner by which the final latching of the contact is achieved. The present invention is directed to an improved, contact stabilized wire connecting block of the type for electrically interconnecting a set cf first conductors to an associated set of seccnd conductors. The electrical connector of this inventicn is illustrated in Figure 1, while sectional views are offered in Figures 2-5 to show the particular manner by which the contained contacts are stabilized therein. The electrical connector 10 according to this invention, and illustrated in Figure 1, comprises a dielectric housing 12, typically formed of plastic, having a pair cf side walls 14, a pair of end walls 16, a first mating face 18, and a contact loading face 20. Within the housing 12, as best seen in the sectional views cf Fires 2-5, are a plurality of cavity slots 22 for receiving and retaining the slotted beam planar contacts 24, as hereinafter described. The cavity slots 22 are provided with a first width, sized to slidable receive the body of contact 24, a second width 26 greater than said first width, and a transition section 28 about midway within the slot. The transition section 28 is angled for reasons to become apparent hereinafter. Along one wall 14 of the housing 12 are a plurality of recesses 30, one for each cavity slot 22, leaving a thin walled section 32 forming part of the wall 34 of cavity slot 22. The recess 30, and hence the thin walled section 32, are aligned with the angled transition section 28. Preferably the recesses 30 are rectangular in configuration for receipt of a comparably configured tool. The preferred slotted beam planar contacts 24 of this invention, to be received and retained within the cavity slots 22, are best illustrated in Figure 1. As known in the art, contacts of this type are typically stamped from a planar strip of sheet metal, such as phosphor bronze, by an operation which advances the strip incrementally through a plurality of work stations, where stamping and peening steps may be performed on the strip. The resulting contact 24, as illustrated in Figure 1, consists of a mid body portion 40, and a pair of insulation cutting and conductor receiving slots 42, 44 formed by the respective pairs of arms 46, 48 extending from the mid body portion 40. The pairs of arms 46, 48 are bifurcated to form furcations 50-50 and 52-52, respectively, with inner portions forming enlarged elongated openings 54, 56 adjacent the mid body portion 40, and with outer portions closing towards each other to form slots 42, 44 having predetermined width characteristics for receiving insulated conductors, not shown. An insulated conductor typically includes a conductive element or wire covered with an insulation, such as, for example, polyethylene, polypropylene, or PVC. Typically, as known in the art, the outermost ends 58, 60 are tapered to form a relatively sharp V-shaped entrance to the conductor receiving slots 42, 44 to thereby facilitate displacing of the insulation and termination of such conductor. To control the width of the conductor receiving slots of certain prior art contacts, peening along the outer edges of the arms has been performed as a way of closing the gap or conductor receiving slot between the arms. In contrast, it was discovered with the present invention that work hardening or peening centrally at the base 62 of the slots 42, 44 offered improved performance. Rather than closing the gap, the gap or slots 42, 44 are opened to a more precisely controlled dimension. Finally, since significant forces are applied to the contacts during termination operations, it is important to be able to fix the contact 24 relative to the housing 12. By this invention, as a further operation of the stamping process, a lance 70 is struck from the mid body portion 40 of the contact 24, where such lance 70 is acutely angled from said mid body portion. In loading the housing 12, as best seen in the sequence illustrated in Figures 2 to 4, the lance 70 is caused to rest against the angled transition section 28. In other words, such angled section functions as a "stop" to further movement of the contact toward first mating face 18. Once the contact 24 is fully seated in the cavity slot 22 (Figure 3), a sharp tool "T" having a tapered tip 72, see Figure 5, may be caused to enter into the recess 30 where such tool "T" severs three sides of the thin walled section 32 which is then hingedly moved or flexed into the opening created by the lance 70. By this arrangement, the partially severed hinged wall section 32 is flexed into engagement with the lance 70, and thereby positioned to resist movement of the contact in the opposite direction. In other words, "stops" have been created against movement in either of the directions where the forces of conductor termination are significant.

Claims: An electrical connector of the type for electrically interconnecting a set of first conductors to an associated set of second conductors, the connector comprising a dielectric housing (12) defined by a pair of side walls (14) and containing a plurality of through cavities (22) therebetween, where each said cavity is adapted to receive a slotted beam planar contact (24), characterized in that said cavities (22) are provided with a first uniform width over a portion of its length, a second portion having a uniform width greater than said first uniform width, and an angled wall transition portion (28) between said uniform portions; and, a like plurality of thin walled sections (32) along one of said side walls, where each said thin walled section (32) is aligned with a corresponding angled wall transition portion (28) within a given cavity (22) each said slotted beam planar contact (24) comprising a mid portion (40) and a pair of opposing end portions (46,48) each containing an insulation displacing slot (54,56) for receiving a conductor, sad mid portion having a lance (70) struck therefrom and angled to abut said angled wall transition portion (28), whereby to secure said contact against movement in a first direction, and said thin walled sections (32) being partially severable to allow hinging movement thereof into the respective cavities (22) adjacent said lances, whereby to secure said contact (24) against movement in a second direction. The electrical connector according to claim 1, wherein the end portions of said slotted beam planar contact (24) include said insulation displacing slot (54,56) at the end and an opening between said slot (54,56) and said mid body portion (40), where the slot ajdacent said opening is work hardened to control the width of said slot. The electrical connector according to claim 1 or 2 wherein said first uniform width is dimensioned to slidably receive said slotted beam planar contact (24). The electrical connector according to claim 1, 2 or 3 wherein said thin walled section (32) is the base of a recess (30) configured to receive a complementary shaped tool ("T") to partially sever said thin walled section (32). The electrical connector according to claim 4 wherein said tool ("T") includes an angled cutting tip (72) which hingedly pushes said thin walled section (32) against its respective lance (70).

Inventors: REED CARL GENE, REED, CARL GENE
Applicants: WHITAKER CORP, THE WHITAKER CORPORATION
Application year: 1994
Main classification: H01R4
IPC codes: H01R43, H01R13, H01R4